1. Field of the Invention
The present invention relates to housings for mounting airbag inflators used in vehicles. More specifically, the present invention relates to housings for mounting airbag inflators securely in a vehicle.
2. Description of Related Art
Safety belts are designed to protect the occupants of a vehicle during events such as automobile collisions. In low-speed collisions, the occupants are generally protected from impact with objects located inside the vehicle such as the windshield, the instrument panel, a door, the side windows, or the steering wheel by the action of the safety belt. In more severe collisions, however, even belted occupants may experience an impact with the car's interior. This generally happens because the momentum of the occupant is so great that impact occurs before a seatbelt can fully decelerate them.
Airbag systems were developed to supplement conventional safety belts by deploying into the space between an occupant and an interior object or surface in the vehicle. The airbag acts to decelerate the occupant, thus reducing the chances of occupant contact with the vehicle's interior.
These airbag systems typically consist of several parts joined in a module. Such modules include an airbag cushion, a sensor, and an airbag inflator. The airbag cushion is typically made of a thin fabric that is folded to fit into a compartment of a steering wheel, dashboard, roof rail, interior panel, or other space in a vehicle. The sensors detect sudden decelerations that are characteristic of an impact. The sensors are set to detect an impact of a predetermined intensity at which it would be desirable for the airbag to deploy.
Upon detection of an impact of sufficient severity, the sensors, or a control unit connected to the sensors, send an electrical signal to the inflator. The inflator uses one of many technologies, including pyrotechnics and pressurized gas, to produce a volume of an inflation gas. The inflation gas is channeled into the airbag, inflating it. An occupant of the vehicle then contacts the airbag, which absorbs the force of the occupant's impact. The inflation gas is vented out of openings in the airbag, deflating it and freeing the occupant to exit the vehicle.
Vehicle manufacturers and suppliers have developed side impact airbag systems to better protect vehicle occupants during side-impact collisions. These airbag systems generally include “inflatable curtains,” which are designed to inflate during an accident to cover the windows, doors, and lateral surfaces of a vehicle. These systems are often mounted within a housing located in the vehicle over the doors.
Typical mounting schemes for inflatable curtains involve mounting the curtain along the edge of the roof of a vehicle. Curtains are often placed behind interior trim such as headliners, A/B/C pillar trim and even weather seals. Care must be taken when designing such mounting schemes to assure that when an airbag is inflated, it is able to properly displace the interior trim and deploy such that it is positioned to protect vehicle occupants. Inflation gas for inflatable curtains is provided by an inflator which is often mounted in the trim near the airbag.
Inflatable curtain airbag inflators have typically been secured to a vehicle by an inflator housing which almost entirely surrounded the inflator. These housings were often cylindrical in shape, and made of metal. Sometimes these housings had a set of radial ridges or rolled grooves on their inside faces to engage the ends of the inflator and prevent movement within the housing. The base end of the inflator was often also secured to the housing by crimping the housing to conform it to the shape and diameter of the base. The housing was then attached to the vehicle by clamps or other attachments. In combination, these measures helped to assure that the inflator would not be expelled from the housing during deployment of the airbag.
In recent years, movement has been made to reduce the size, weight, and material requirements of inflator housings. This has included the development of two-piece diffuser designs for airbag inflators. These designs allow an airbag cushion to be attached directly to the airbag inflator instead of requiring attachment to the housing. These diffuser designs thus render it possible to use less bulky inflator housings. Such designs may potentially provide a significant cost savings while also reducing the weight of the airbag module.
Such housing designs enclosing less than the entire inflator are more difficult to mount securely to a vehicle. This difficulty stems in part from instability caused by securing only one end of the airbag inflator. Such instability may be especially noticeable when the inflator has been activated and is discharging inflation gas.
Without having a large, substantial housing, it may be more difficult to properly anchor an inflator. Solutions to this problem generally require custom-sizing of the inflator housing using manual labor. Such solutions include clamping a bracket around a region of the inflator such as the base end, and manually tightening and attaching the bracket to provide sufficient clamping force to hold the inflator in place. This solution requires several manual steps. Such manual steps may add to the production and installation time required for use of the inflator housing. They may also increase the cost. Other common solutions also require additional parts and manual steps to attach an inflator to an inflator housing.
Accordingly, it would be an advancement in the art to provide an airbag inflator housing that rigidly holds an airbag inflator in place during storage and deployment. Additionally, it would be beneficial to provide an airbag inflator housing that is inexpensive to manufacture, simple to install, and is lighter in weight than currently used in airbag inflator housings. Such an airbag inflator housing is disclosed herein.